Lab 14 HW

The ventral rami of spinal nerves ________ form the major nerve plexuses.

C1 through T1 and L1 through S4

In addition to its role in spinal reflex activity, the spinal cord also _________.

Contains sensory and motor tracts traveling to and from higher nervous centers

The spinal cord extends from the foramen magnum of the skull to the first or second lumbar vertebra, where it terminates in the ________.

Conus medullaris

These fiber tracts carry signals about voluntary movement to the spinal cord.

corticospinal tracts

These fiber tracts run between the dorsal horns

dorsal white columns

Somatosensory functions are carried out in this part of the spinal cord.

dorsal white columns and dorsal horns

The meninges that cover the spinal cord from outermost to innermost are ________.

dura mater, arachnoid mater, pia mater

This extension of one of the meninges covering the spinal cord attaches it to the coccyx.

filum terminale

In cross section, the ____ matter of the spinal cord looks like a butterfly or the letter H.

gray

These horns of the spinal cord are present only in the thoracic and lumbar regions.

lateral

Nerves serving the lower limb issue from this enlargement of the spinal cord.

lumbar

Ventral roots of spinal nerves are purely or primarily ____.

motor

This nerve, arising from the cervical plexus, is essential for normal breathing

phrenic

This nerve of the brachial plexus supplies all the extensor muscles of the upper limb.

radial

Fiber tracts conducting impulses to the brain are called ascending or _____ tracts

sensory

What functional type of neuron is found in the dorsal root ganglion?

sensory

There are ______ enlargements of the spinal cord.

2

How many pairs of spinal nerves are present in humans ?

31

How many pairs of spinal nerves does the human have ?

31

There are ____ pairs of cranial nerves and ____ pairs of lumbar spinal nerves.

8,5

Damage to the lumbar plexus is likely to affect _______.

Extension of the knee

The cell bodies of sensory neurons are found in an enlarged area of the dorsal root called the gray commissure.

False

The femoral nerve is the largest nerve from the sacral plexus.

False

Transaction of the dorsal roots of spinal nerves C5 through T1 results in _______.

Loss of sensation in the upper limb on the same side of the body.

The spinal nerves are _________nerves.

Mixed

The ventral rami of all spinal nerves except T2 through T12 form complex networks of nerves known as ___________.

Plexuses

Wrist drop results in an inability to extend the hand at the wrist. Which nerve would most likely be affected in this injury?

Radial nerve

The dorsal rami of spinal nerves __________.

Serve the skin and muscles of the posterior body trunk

The varicella zoster virus causing chicken pox can stay dormant in the sensory neurons in the dorsal root ganglion. It can get reactivated later on in life causing _______.

Shingles

These ascending (sensory) tracts are the most lateral ones between the dorsal and ventral roots of the spinal cord.

Spinocerebellar tracts

Because the spinal nerves arise from fusion of the ventral and dorsal roots of the spinal cord, and contain motor and sensory fibers, all spinal nerves are considered mixed nerves.

True

The odd tingling sensation that you experiences when you hit the funny bone is die to trauma to the ______ nerve.

Ulnar

Severe injuries to the ________ plexus cause weakness or paralysis of the entire upper limb.

brachial

The following represents a collection of spinal nerve roots hanging from the inferior end of the spinal cord.

cauda equina

The sciatic nerve divides into the tibial and _______ nerves.

common fibular

At the level of the first or second lumbar vertebra the spinal cord terminates in a structure called the ________.

conus medullaris